1. Field of the Invention
The invention relates to the installation structure of a pedal stroke sensor for detecting the deflection angle of a pedal.
2. Description of the Related Art
In an automobile (vehicle), pedals are fixed under the dashboard so that the driver may brake and accelerate the vehicle by stepping on these pedals.
In recent years, it has become more and more common to electrically control a device according to a detected signal that is detected by a pedal stroke sensor for detecting pedal deflection.
Many of such pedal stroke sensors, as described in Kokai No. 3-67315, are fixed to a pedal so that the pivot of the pedal stroke sensor is fitted to that of the pedal. A sensor arm (component radially protruding from the pivot of the sensor) serving as an input section of the pedal stroke sensor is engaged with a part of the pedal, and thus transmits pedal deflection to the pedal stroke sensor.
However, a dashboard to which pedals are fixed is equipped with a lot of devices in front of the driver's feet, so that the pedal stroke sensor often cannot be installed near the pedal.
In such a case, the pedal stroke sensor is placed in a pedal bracket to be located away from the pedal, and is installed so that an engaging member attached to the pedal and the sensor arm of the pedal stroke sensor are slidably engaged together in order to actualize the transmission by engagement. By this means, pedal deflection can be transmitted to the pedal stroke sensor located in an unobtrusive place.
The pedal stroke sensor is required to accurately detect a pedal deflection angle between the initial position of the pedal and the pressed position of the pedal.
The structure in which the sensor arm and the engaging member are slidably engaged together makes it possible to detect a pedal deflection angle with high accuracy when distance between the sensor arm and the pedal is short. On the other hand, if the sensor arm and the pedal are located far away from each other, the accurate detection is difficult.
In addition, uneven contact between the sensor arm and the engaging member during a pedal stroke makes a gap between these two components. As a consequence, even if the above-mentioned structure is established, backlash easily occurs between components. This causes a position gap between the initial position of the pedal and the position to which the pedal is returned after being pressed, so that there is a possibility that the pedal stroke sensor fails to detect an exact pedal deflection angle.